Gravity-sensitive multiple contact switches



Feb. 11', 1958 J. w. HURON 2,823,367

GRAVITY-SENSITIVE MULTIPLE CONTACT SWITCHES Filed June 25, 1956 iINVENTOR.

United States Patent GRAVITY-SENSITIVE MULTIPLE CONTACT SWITCHES JamesW. Huron, Los Angeles, Calif.

Application June 25, 1956, Serial No. 593,593

Claims. (Cl. 340-52) This invention relates to automotive electricalcircuits and the switches used therein, and more particularly to agravity operated switch utilizing a liquid conductor and being adaptedto de-energize the battery and magneto ignition systems of an automobileand sound an alarm signal in case the vehicle in which the apparatus isinstalled is upset or tilted laterally beyond a certain point relativeto its normally upright position.

Highway patrol and insurance company records indicate that in a highpercentage of cases the upsetting of a vehicle in an accident isfollowed by fire; and that fire is quite often the major cause of damageand loss of life in serious highway accidents.

Most often the fires following upsets occur because the engine remainsrunning or the starter and ignition circuits are not de-energized andserve to ignite the fumes of displaced fuel.

Furthermore, in accidents in which fire is not an important factor,scores of motorists each year fail to negotiate turns on mountainousroads and drive unseen over the tops of embankments, coming to rest downthe hill side far below the line of vision of other motorists where theyremain injured or entrapped for hours or days before being seen andrescued.

My invention has been made with the foregoing considerations in mind andcan be said to have a plurality of important objectives.

One important object of my invention is the provision of a device and anelectrical circuit therewith being adapted to de-energize theconventional ignition circuit of a vehicle when tipped beyond apredetermined point relative to its normally upright position.

Another important object of my present invention is the provision of adevice of the character described which is further adapted tode-energize the supplementary magneto ignition circuit in vehicleshaving both battery and magneto systems in cases of upsets or extremedisplacement from the normal upright positioning of a vehicle.

A further important object of my invention is the provision of a deviceand the electrical circuitry associated therewith which is adapted tode-energize the ignition systems, as mentioned, and furthermore toenergize an alarm circuit to attract the attention of passersby.

An additional important object of my invention is the provision of adevice of the character described being adapted for fully automaticoperation, and being dust and moisture proof and requiring no adjustmentor service when properly installed.

And a still further important object of my invention is the provision ofa switching device as previously described which is conformed oftransparent body material to facilitate checking and inspection.

In brief, my invention includes a rectangular block of transparentnon-conductive material having parallel front and back faces normallyvertically disposed and having therebetween longitudinally extendedtopand bottom surfaces, and shorter opposite vertical ends. A generallyV- shaped cavity having serif-like enlargements of its two upwardlydisposed ends and its central bottom portion is centered within thesolid block of the main body intermediate of the front and back facesthereof, and a pair of electrodes is disposed through the body materialinto each of the upper enlargements from the top and from each end, andinto the central enlargement from the bottom. A quantity of mercurysufiicient to fill the central bottom portion of the cavity to a pointslightly above the inner convergence of its two diagonally disposedsides is sealed therein after the air is exhausted and replaced by aninert gas.

The switch is installed on any solid transverse structural member of thevehicle, such as the engine compartment firewall, with the bottom of theswitch substantially parallel to the road surface.

The electrodes are wired into the electrical system so that theoperation of the vehicle is normal as long as it remains in an uprightposition, but if it is tilted laterally in either direction sufficientlyto cause the mercury to run down either of the diagonal sides of thecavity, the bottom electrodes break the conventional ignition circuit,and the contacts disposed within the upper end portion filled withmercury serve to ground out the magneto ignition system and energize analarm device.

Other important objects of this invention will become apparent in thefollowing detailed description of one embodiment thereof when read withreference to the accompanying drawings, of which:

Figure 1 is a diagrammatic front elevational view of a mercury switchconstructed according to my invention, the switch being disposed in thenormally upright position;

Figure 2 is a view similar to that of Figure 1 showing the dispositionof the mercury within the switch cavity when tilted laterally;

Figure 3 is a cross sectional view taken along the line and in thedirection indicated by the arrows 33 in Figure 1;

Figure 4 is a plan view of the device as it would appear in the normalupright position seen in Figure l; and,

Figure 5 is a schematic wiring diagram indicating the manner in whichthe device cooperates with various elements and circuits in aconventional automotive electrical system.

Reference is again made to Figure l in which the switch constructedaccording to my invention is designated by the numeral 10 which will beused hereinafter to indicate the solid rectangular body portion of thedevice including its top 11, bottom 12, ends 13 and 14, and the flatrectangular frontal face 15.

As has been previously indicated, the solid body portion 10 is conformedof transparent material, and for the sake of illustrative clarity theV-shaped cavity therein is shown in solid rather than dotted lines.

Again in Figure 1, the cavity is seen to be comprised of two upwardlyextended diagonal channels 16 and 17, the inner edges of which convergeat the central point 18 below which the channels merge into an enlargedbasal portion 19 which is indicated in the figure as being filled with aquantity of mercury 20 which surrounds a pair of electrodes 21 and 22which are extended through the bottom 12 into the basal area 19 of thecavity.

Each of the channels 16 and 17 is enlarged at its upper termination asshown at 23 and 24 and pairs of electrodes designated as 25-26 and 27-28are entered therein through the top 11 with single electrodes 29 and 30disposed through the sides 13 and 14 respectively into the enlargedterminal areas 23 and 24.

Particular attention is directed to Figures 3 and 4 which show theparticular conformation of the enlarged terminal areas 23 and 24 of thechannels 17 and 16 and the sectional contour of the basal terminal area19 which are seen to be extended laterally substantially beyond thestraight sides of the channels. Also significant is the manner in whichthe basal area 19 is conformed with vertical sides as seen at 31 and 32in Figure l.

The enlarged terminal areas at 19, 23 and 24 are provided for thepurpose of concentrating as much of the mercury as possible about theelectrodes disposed in the respective cavities when the mercury isentered therein, and the straight sides at 31 and 32 are provided tokeep the mercury when disposed in the basal area 19 from flowingupwardly in either of the channels as the vehicle in which the device isinstalled sways to either side.

All of the electrodes are positioned at the time the body 10 isconformed so that they are held in place by the body material andprovide airtight seals therewith.

A predetermined amount of mercury is disposed in the basal terminal area19 of the cavity and air remaining in the cavity is exhausted therefromand replaced with an inert gas in order to prolong the conductiveefficiency of the electrodes.

I Referring again to Figure 1, it will be observed that the quantity ofmercury as shown at 20 is snlficient to extend upwardly into thechannels 16 and 17 above the juncture of the inner sides thereof seen at18. This is done for the purpose of confining the mercury to asubstantial extent within the basal area 19 and keeping it from flowingas previously mentioned up to the channels 16 and 17 in response to theswaying movements of the vehicle. The projection of the electrodes intothe bottom of the cavity also serves to stabilize the positioning of themercury puddle.

When the device is tilted as shown in Figure 2, the mercury 20 runsthrough the downwardly disposed channel 16 and simultaneously breaks theelectrical circuit between the electrodes 21 and 22, and makes twocircuits by means of the electrodes 27, 28 and 30.

Attention is now directed to Figure which is a schematic diagram showingthe safety system of my invention and is seen to include the switch 10,an electrical alarm signal 33, a conventional ignition switch 34, amagneto out out switch 35 serving the magneto which is showncollectively at 36, a conventional engine ignition system showncollectively at 37, and the battery 38 and ground connections 39 and 40.

As will be readily understood from an inspection of the diagram, as longas the switch remains in the upright position as shown in Figure 5, theoperation of the ignition system is normal. Current from the battery 38is directed through the conductor 41 to the alarm signal 33 and to themercury in the basal cavity area 19 of the switch 10, and thence throughthe conductor 42 to the manually operated ignition switch 34 closure ofwhich directs current through the conductor 43 to the ignition system 37which, in turn, is grounded at 40.

As long as the switch 14 remains in the upright position, the operationof the system, as has been said, is normal, but when the switch issufiiciently tipped laterally in either direction to cause the mercury20 to run through either of the channels 16 or 17 and into the endthereof, the circuit is broken at the electrodes 21 and 22 in the baseof the switch, and the engine is stopped.

Attention is directed to the *fact that corresponding electrodes in theupper portions 23 and 24 of the channels 16 and 17 re connected inparallel so that either set of electrodes is adapted to perform theswitching functions involved in the complete safety system of myinvention. The center electrodes 26 and 27 both communicate through theconductor 39a with the ground 39; the inner electrodes and 28 are joinedat 44 and communicate with the magneto side of the switch; and theelectrodes 29and disposed outwardly through the ends of the switchcommunicate through the conductor 45 with the ground side of the alarmsignal 33.

Thus, as will be readily understood, if the switch is tipped laterallyso that the mercury mass 20 moves through the channel 16 as indicated inFigure 2, the magneto circuit represented by the electrode 28 isgrounded through the electrode 27 and the conductors 39-a and 39, andthe electrode 30 is similarly grounded thereby activating aflow ofcurrent through the signal 33 from the battery 38 effective to sound thealarm signal.

Operation of the system in case the switch 10 were tilted to the rightand the mercury 20 flowed through the channel 17 into contact with theelectrodes 25, 26 and 29, would be identical.

Since the purpose of the alarm signal is to attract attention in casethe vehicle were disabled in a secluded or inconspicuous location offthe highway, the device would be adapted preferably to emit a sustainedand distinctive signal which would arouse the curiosity of passersby orbe immediately recognizable as a distress signal. Similarly a flashinglight is used as the signal means in prototype systems now being testedon vehicles used largely in night driving across desert and rollingterrain.

To provide a further element of safety covering cases in which thevehicle might be tilted longitudinally rather than laterally, two of theswitches such as 10 are installed in the vehicle, being positionedtherein at right angles to each other.

Although in order to comply with the statute my invention has been setforth in considerable detail concerning one particular embodiment, it isto be understood that these details are subject to change andmodification and the embodiment is open to substantial variation, andthe invention itself is amenable to adaptation into a plurality ofembodiments and therefore is not to be restricted to the form specifiedherein nor limited in any manner except as may be indicated by theextent of the appended claims.

What I claim as my invention is:

1. A switch for use in an automotive electrical system including anignition unit, comprising: a solid, generally rectangular block ofelectrically non-conductive material having therein a closed V-shapedcavity including two oppositely disposed diagonal channels having theirupper ends spaced apart adjacent the top of said block and converging inthe lower central area of the block, said cavity further including awellconstituting the bottom portion thereof and joining the convergingportions of said channels, said well having, at the respective sideextremities thereof, substantially vertical walls joined to the outerwalls of said channels; a plurality of electrodes extending through thebottom of said block and into said well; and a quantity of electricallyconductive liquid disposed in said cavity, covering said electrodes,extending above and sealed to the point of intersection of the innerwalls of said channels, and thereby isolating the spaces within saidchannels from one another above said body of liquid, said vertical sideextremity walls of said well functioning cooperatively with the sealingof said liquid body to said point of intersection of the channels, toresist deflection of the body of liquid outwardly into either of saidchannels in response to swaying movement communicated to said switch inthe common plane of said channels; said electrodes being normallyconnected by said liquid body to constitute a series connection to saidignition unit and becoming electrically isolated upon tilting of theswitch to a position in which the liquid may occupy the full length ofone of said channels.

2. A switch as defined in claim 1, including electrodes extending intothe upper ends of said channels for actuating an alarm circuit upon theoccurrence of said tilting. f 3. A switch as defined in claim 2, whereinthere are a pair of electrodes at the upper end of each of said channelsand including an alarm circuit in which an electrode ,of each of saidpairs is disposed in parallel with one side of an alarm device and theother electrode of each of said pairs is disposed in parallel with asource of electrical power for energizing said alarm device.

4. A switch for use in the ignition system of an automotive vehicle,comprising: a casing of electrically non-conductive material havingtherein a V-shaped cavity including two oppositely disposed diagonalchannels having their upper ends spaced apart adjacent the top of saidcasing and converging to an intersection in the lower central area ofthe casing, said channels having enlarged recesses in their upper ends,and said cavity having a well constituting an enlargement of saidintersection; a plurality of electrodes extending through the bottom ofsaid casing and into said well in spaced relation, for constituting aseries connection in said ignition system; a group of electrodes in eachof the upper corners of said casing, each group including at least onepair of electrodes extending into the upper end portion of each of saidchannels, at least one electrode of each pair being disposed in theenlarged recess of said upper end, said pairs of electrodes beingadapted for connection in parallel into an alarm circuit; and a quantityof electrically conductive liquid disposed in said cavity, covering saidelectrodes of said bottom well, normally establishing a connectionbetween the same, and adapted, upon tilting of the switch upon eitherside thereof, to evacuate said well sufliciently to break the connectionbetween the contacts of said well and to travel to the end of thechannel which is lowered as the result of said tilting, so as to fillthe recess in the upper end of said lowered channel and therebyestablish an alarm connection between the pair of electrodes in saidupper end portion of said lowered channel.

5. In combination with an automotive ignition system including anignition unit and a battery and electric current generator connected inseries to said ignition unit for alternatively energizing the same, aswitch comprising a solid. generally rectangular block of electricallynonconductive material having therein a V-shaped cavity including twooppositely disposed diagonal channels having their upper ends spacedapart adjacent the top of said block and converging to an intersectionin the lower central area of the block, said cavity further including awell constituting an enlargement of said intersection, and includingenlarged recesses at the upper ends of said channels; a quantity ofelectrically conductive liquid disposed in said cavity and normallyfilling said well; an alarm device; a pair of electrodes extendingthrough the bottom of said block into said cavity and normally connectedby said liquid to close a circuit between said battery and said ignitionunit; groups of electrodes extending through each of the upper cornersof said block and into the respective upper ends of said respectivechannels, each of said groups of electrodes consisting in threeelectrodes arranged in two pairs with one of the electrodes being commonto both pairs for each group; one pair of electrodes of each group beingarranged to establish a connection from said battery to said alarmdevice when connected by said body of liquid and the other pair of eachgroup of electrodes being adapted to establish a connection to saidalarm device from said current generator upon being connected by saidliquid.

References Cited in the file of this patent UNITED STATES PATENTS1,640,695 Dolly Aug. 30, 1927 1,915,406 Coursey June 27, 1933 2,056,150Anguish et al Oct. 6, 1936 2,100,105 Lee et al. Nov. 23, 1937 2,304,608Smythe Dec. 8, 1942 2,774,835 Staley Dec. 18, 1956

